NoState Prefetch: nostate prefetch browser tests.

chrome/browser/prerender/prerender_nostate_prefetch_test.cc

Index: chrome/browser/prerender/prerender_nostate_prefetch_test.cc
diff --git a/chrome/browser/prerender/prerender_nostate_prefetch_test.cc b/chrome/browser/prerender/prerender_nostate_prefetch_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..610b7752392778e235ec7d6c695fdc91e56fdf44
--- /dev/null
+++ b/chrome/browser/prerender/prerender_nostate_prefetch_test.cc
@@ -0,0 +1,467 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/command_line.h"
+#include "base/strings/string_split.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/browser/prerender/prerender_manager_factory.h"
+#include "chrome/browser/prerender/prerender_test_utils.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/task_manager/task_manager_browsertest_util.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/grit/generated_resources.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/common/url_constants.h"
+#include "content/public/test/browser_test_utils.h"
+#include "net/base/escape.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/test/embedded_test_server/request_handler_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/base/l10n/l10n_util.h"
+
+using prerender::test_utils::CreateCountingInterceptorOnIO;
+using prerender::test_utils::DestructionWaiter;
+using prerender::test_utils::RequestCounter;
+using prerender::test_utils::TestPrerender;
+using prerender::test_utils::TestPrerenderContents;
+using task_manager::browsertest_util::WaitForTaskManagerRows;
+namespace prerender {

[pasko, 2016/09/30 18:29:21]

nit: extra empty line above namespace

[mattcary, 2016/10/03 10:58:35]

Done.

+
+// The various uses of URLs in these tests (the test server, request capture,
+// etc) are fussy about relative versus absolute paths. With the exception of

[pasko, 2016/09/30 18:29:21]

fussy? that's very concrete and easy to understand. Am I being fussy at
explaining what I want or just ironic?

[mattcary, 2016/10/03 10:58:35]

Acknowledged.

+// kPrefetchLoaderPath, which is only used in PrerenderTestURLImpl, all other
+// paths should be relative.
+const char kPrefetchImagePage[] = "prerender/prefetch_image.html";
+const char kPrefetchLoopPage[] = "prerender/prefetch_loop.html";
+const char kPrefetchJpeg[] = "prerender/image.jpeg";
+const char kPrefetchLoaderPath[] = "/prerender/prefetch_loader.html";
+const char kPrefetchPage[] = "prerender/prefetch_page.html";
+const char kPrefetchPage2[] = "prerender/prefetch_page2.html";
+const char kPrefetchPng[] = "prerender/image.png";
+const char kPrefetchScript[] = "prerender/prefetch.js";
+const char kPrefetchScript2[] = "prerender/prefetch2.js";
+const char kPrefetchSubresourceRedirectPage[] =
+    "prerender/prefetch_subresource_redirect.html";
+
+const char kPageBool[] = "pageBool";
+const char kScriptBool[] = "scriptBool";
+
+class NoStatePrefetchBrowserTest
+    : public test_utils::PrerenderInProcessBrowserTest {
+ public:
+  NoStatePrefetchBrowserTest() {}
+
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    PrerenderInProcessBrowserTest::SetUpCommandLine(command_line);
+    command_line->AppendSwitchASCII(
+        switches::kPrerenderMode, switches::kPrerenderModeSwitchValuePrefetch);
+  }
+
+  // Set up a request counter for the path.
+  void CountRequestFor(const std::string& path, RequestCounter* counter) {
+    GURL::Replacements replacement;
+    replacement.SetPathStr(path);
+    const GURL url = src_server()->base_url().ReplaceComponents(replacement);
+    base::FilePath url_file =
+        ui_test_utils::GetTestFilePath(base::FilePath(), base::FilePath(path));
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(&CreateCountingInterceptorOnIO, url, url_file,
+                   counter->AsWeakPtr()));
+  }
+
+  // Fetches a boolean value from javascript. Returns whether the fetch
+  // succeeded; the value of the variable is returned in value. If
+  // javascript_variable does not exist, this returns false and value is
+  // unchanged. The function checks that script execution works.
+  bool GetJavascriptBoolean(const std::string& javascript_variable,

[pasko, 2016/09/30 18:29:20]

static? why does this need to be in the NoStatePrefetchBrowserTest? Putting this
(and below) functions to anonymous namespace would make the dependencies
clearer.

[mattcary, 2016/10/03 10:58:35]

Done.

+                            content::WebContents* web_contents,
+                            bool* value) {
+    // In order to detect unknown variables we need a three-valued return.

[pasko, 2016/09/30 18:29:20]

nit: ... a three-valued return is needed.

[mattcary, 2016/10/03 10:58:34]

Done.

+    int result;
+    EXPECT_TRUE(content::ExecuteScriptAndExtractInt(

[pasko, 2016/09/30 18:29:21]

should this rather be a fatal failure? It does not really make much sense to
continue the test if this functionality is not working. In the current form we
risk crashing after EXPECT_TRUE fails. This may be a problem if the tests are
all run in the same process (even though this consideration might be
hypothetical for these particular tests).

[mattcary, 2016/10/03 10:58:35]

Yes, but it won't compile! ASSERT_TRUE can only be used directly from a test
function as the macro expands to include a void return statement. At least
that's as much as I could tell from the error message.

I'd be happy to use another suggestion for assert macro as I had the same
feeling as you, but it wasn't clear to me what the right macro to use was.

[droger, 2016/10/03 11:07:13]

The relevant gtest doc is here:
https://github.com/google/googletest/blob/master/googletest/docs/AdvancedGuid...

I think the options are:
- use a macro to add a failure here, such as FAIL(), and call HasFatalFailure()
at the call site.
- change the return value to convey fatal failures (such as return an error code
instead of a bool), and then use ASSERT macros at the call site.

Both are a bit clunky unfortunately.

[pasko, 2016/10/03 18:54:16]

Thanks for investigation, folks. Agreed that ASSERT_NO_FATAL_FAILURE /
HasFatalFailure() is burdensome and does not buy us much.

[mattcary, 2016/10/04 08:25:12]

Acknowledged.

+        web_contents,
+        "try { if (" + javascript_variable + ") { " +
+            "window.domAutomationController.send(1) } else { " +
+            "window.domAutomationController.send(0); } } catch(err) {" +
+            "window.domAutomationController.send(2) }",
+        &result));
+    if (result == 2) {
+      // This means an exception was caught, usually because of a missing
+      // variable.
+      return false;
+    }
+    *value = (result == 1);
+    return true;
+  }
+
+  // As above, but just checks for a missing variable.
+  bool JavascriptVariableMissing(const std::string& javascript_variable,
+                                 content::WebContents* web_contents) {
+    bool unused;
+    return !GetJavascriptBoolean(javascript_variable, web_contents, &unused);
+  }
+
+ private:
+  ScopedVector<TestPrerender> PrerenderTestURLImpl(
+      const GURL& prerender_url,
+      const std::vector<FinalStatus>& expected_final_status_queue,
+      int expected_number_of_loads) override {
+    base::StringPairs replacement_text;
+    replacement_text.push_back(
+        make_pair("REPLACE_WITH_PREFETCH_URL", prerender_url.spec()));
+    std::string replacement_path;
+    net::test_server::GetFilePathWithReplacements(
+        kPrefetchLoaderPath, replacement_text, &replacement_path);
+    GURL loader_url = src_server()->GetURL(replacement_path);
+
+    ScopedVector<TestPrerender> prerenders = NavigateWithPrerenders(
+        loader_url, expected_final_status_queue, expected_number_of_loads);
+
+    TestPrerenderContents* prerender_contents = prerenders[0]->contents();
+    CHECK(prerender_contents);
+    // Check that the prerender contents final status is unchanged from its
+    // default value, meaning that the contents has not been destroyed.
+    EXPECT_EQ(FINAL_STATUS_MAX, prerender_contents->final_status());
+
+    EXPECT_EQ(expected_number_of_loads, prerenders[0]->number_of_loads());
+
+    return prerenders;
+  }
+};
+
+// Checks that when the prefetch page is loaded in full, javascript values are

[pasko, 2016/09/30 18:29:20]

s/prefetch/prefetcher/ or 'the initial page requesting the prefetch' for extra
clarity?

[mattcary, 2016/10/03 10:58:34]

Done.

+// set as expected. This checks that our test system is working as expected.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, CheckJavascript) {
+  ui_test_utils::NavigateToURL(
+      current_browser(), src_server()->GetURL(MakeAbsolute(kPrefetchPage)));
+  content::WebContents* web_contents =
+      current_browser()->tab_strip_model()->GetActiveWebContents();
+
+  // Confirm we can get true and false values.
+  bool value = false;
+  EXPECT_TRUE(GetJavascriptBoolean(kPageBool, web_contents, &value));
+  EXPECT_TRUE(value);
+  value = true;
+  EXPECT_TRUE(GetJavascriptBoolean("pageAntiBool", web_contents, &value));
+  EXPECT_FALSE(value);
+
+  // Confirm a value from the script is plumbed through.
+  value = false;
+  EXPECT_TRUE(GetJavascriptBoolean(kScriptBool, web_contents, &value));
+  EXPECT_TRUE(value);
+
+  // Confirm that the expected happens when a value doesn't exist.
+  EXPECT_TRUE(JavascriptVariableMissing("iDontExist", web_contents));
+}
+
+// Checks that a page is correctly prefetched in the case of a
+// <link rel=prerender> tag and then loaded into a tab in response to a
+// navigation, when NoState Prefetch is enabled, but that the page is not loaded
+// (which confirmed by checking that javascript is not executed).
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchSimple) {
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  RequestCounter main_counter;
+  CountRequestFor(kPrefetchPage, &main_counter);
+
+  std::unique_ptr<TestPrerender> test_prerender =
+      PrerenderTestURL(kPrefetchPage, FINAL_STATUS_APP_TERMINATING, 1);
+  main_counter.WaitForCount(1);
+  script_counter.WaitForCount(1);
+
+  content::WebContents* contents =
+      test_prerender->contents()->prerender_contents();
+  content::WebContents* active_contents =
+      current_browser()->tab_strip_model()->GetActiveWebContents();
+  EXPECT_TRUE(JavascriptVariableMissing(kPageBool, contents));
+  EXPECT_TRUE(JavascriptVariableMissing(kScriptBool, contents));
+  EXPECT_TRUE(JavascriptVariableMissing(kPageBool, active_contents));
+  EXPECT_TRUE(JavascriptVariableMissing(kScriptBool, active_contents));
+  histogram_tester().ExpectTotalCount("Prerender.PerceivedPLT", 1);
+  histogram_tester().ExpectBucketCount(
+      "Prerender.websame_NoStatePrefetchResponseTypes",
+      4 /* cacheable, main resource */, 1);
+  histogram_tester().ExpectBucketCount(
+      "Prerender.websame_NoStatePrefetchResponseTypes",
+      0 /* cacheable, non-main resource */, 1);
+  histogram_tester().ExpectTotalCount("Prerender.none_MainResourceRedirects",
+                                      0);
+  histogram_tester().ExpectTotalCount("Prerender.none_SubResourceRedirects", 0);
+}
+
+// Check the histograms on reuse of a prefetch.

[pasko, 2016/09/30 18:29:20]

More concrete: Checks that the TTFCP histograms are updated on use of a
prefetch.

[mattcary, 2016/10/03 10:58:35]

Done.

+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest,
+                       PrefetchReusedWarmHistograms) {
+  PrerenderTestURL(kPrefetchPage, FINAL_STATUS_APP_TERMINATING, 1);
+  GetTestPrerenderManager()->AdvanceTime(base::TimeDelta::FromSeconds(10));
+  ui_test_utils::NavigateToURL(
+      current_browser(), src_server()->GetURL(MakeAbsolute(kPrefetchPage)));
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchTTFCP.Warm.Cacheable", 1);
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchTTFCP.Cold.Cacheable", 0);
+}
+
+// Check the histograms on reuse of a prefetch.

[pasko, 2016/09/30 18:29:20]

Checks

[mattcary, 2016/10/03 10:58:35]

Done.

+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest,
+                       PrefetchReusedColdHistograms) {
+  PrerenderTestURL(kPrefetchPage, FINAL_STATUS_TIMED_OUT, 1);
+  GetTestPrerenderManager()->AdvanceTime(base::TimeDelta::FromSeconds(600));
+  ui_test_utils::NavigateToURL(
+      current_browser(), src_server()->GetURL(MakeAbsolute(kPrefetchPage)));
+
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchTTFCP.Warm.Cacheable", 0);
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchTTFCP.Cold.Cacheable", 1);
+}
+
+// Test that we prefetch an img tag in body using our particular

[pasko, 2016/09/30 18:29:21]

Tests
avoid we, our

why using polluting words like 'particular'? Wouldn't it be better to load this
space occupied by the comment with something more concrete? Another option:
remove the words after the word 'body'.

[mattcary, 2016/10/03 10:58:35]

Done.

+// prerender_prefetch_image.html setup.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchImage) {
+  RequestCounter image_counter;
+  CountRequestFor(kPrefetchJpeg, &image_counter);
+  base::StringPairs replacement_text;
+  replacement_text.push_back(
+      std::make_pair("REPLACE_WITH_IMAGE_URL", MakeAbsolute(kPrefetchJpeg)));
+  std::string main_page_path;
+  net::test_server::GetFilePathWithReplacements(
+      kPrefetchImagePage, replacement_text, &main_page_path);
+  // Note that we can't CountRequestFor the main page as we use the test server
+  // for handling the image url replacement.
+  PrerenderTestURL(main_page_path, FINAL_STATUS_APP_TERMINATING, 1);
+  image_counter.WaitForCount(1);
+}
+
+// Check cross-domain prefetching by looking at histograms.

[pasko, 2016/09/30 18:29:20]

Checks that .. cross-domain prefetching does X when Y.

[mattcary, 2016/10/03 10:58:35]

Done.

+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchCrossDomain) {
+  static const std::string secondary_domain = "www.foo.com";
+  host_resolver()->AddRule(secondary_domain, "127.0.0.1");
+  GURL cross_domain_url(base::StringPrintf(
+      "http://%s:%d/%s", secondary_domain.c_str(),
+      embedded_test_server()->host_port_pair().port(), kPrefetchPage));
+  PrerenderTestURL(cross_domain_url, FINAL_STATUS_APP_TERMINATING, 1);
+  histogram_tester().ExpectTotalCount("Prerender.PerceivedPLT", 1);
+  histogram_tester().ExpectTotalCount("Prerender.none_PerceivedPLT", 1);
+  histogram_tester().ExpectTotalCount(
+      "Prerender.webcross_PrerenderNotSwappedInPLT", 1);
+}
+
+// Check that we support simultaneous prefetch.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchSimultaneous) {
+  RequestCounter first_main_counter;
+  CountRequestFor(kPrefetchPage, &first_main_counter);
+  RequestCounter second_main_counter;
+  CountRequestFor(kPrefetchPage2, &second_main_counter);
+  RequestCounter first_script_counter;
+  CountRequestFor(kPrefetchScript, &first_script_counter);
+  RequestCounter second_script_counter;
+  CountRequestFor(kPrefetchScript2, &second_script_counter);
+
+  // The first prerender is marked as canceled as when the second starts, it
+  // sees that the first has been abandoned (presumably because we detach
+  // immediately and so it dies quickly).
+  PrerenderTestURL(kPrefetchPage, FINAL_STATUS_CANCELLED, 1);
+  PrerenderTestURL(kPrefetchPage2, FINAL_STATUS_APP_TERMINATING, 1);
+  first_main_counter.WaitForCount(1);
+  second_main_counter.WaitForCount(1);
+  first_script_counter.WaitForCount(1);
+  second_script_counter.WaitForCount(1);
+  histogram_tester().ExpectTotalCount("Prerender.PerceivedPLT", 2);
+  histogram_tester().ExpectTotalCount("Prerender.none_PerceivedPLT", 2);
+}
+
+// Check that we correctly handle a prefetch to a nonexisting page.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchNonexisting) {
+  PrerenderTestURL("nonexisting-page.html", FINAL_STATUS_APP_TERMINATING, 0);
+  // TODO(mattcary): we fire up a prerenderer before we discover that the main
+  // page doesn't exist, we still count this as a prerender. Also we don't fail
+  // the renderer (presumably because we've detached the resource, etc). Is this
+  // what we want?
+  histogram_tester().ExpectTotalCount("Prerender.PerceivedPLT", 1);
+}
+
+// Check that we follow a 301 redirect.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, Prefetch301Redirect) {
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  PrerenderTestURL(
+      "/server-redirect/?" +
+          net::EscapeQueryParamValue(MakeAbsolute(kPrefetchPage), false),
+      FINAL_STATUS_APP_TERMINATING, 1);
+  script_counter.WaitForCount(1);
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchMainResourceRedirects", 1);
+}
+
+// Check that we follow a subresource 301 redirect.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, Prefetch301Subresource) {
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  PrerenderTestURL(kPrefetchSubresourceRedirectPage,
+                   FINAL_STATUS_APP_TERMINATING, 1);
+  script_counter.WaitForCount(1);
+  histogram_tester().ExpectTotalCount(
+      "Prerender.websame_NoStatePrefetchMainResourceRedirects", 1);
+}
+
+// Check that we don't follow a client redirect.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchClientRedirect) {
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  // We use a sentinel via a complete load kPrefetchPage2. Otherwise we end
+  // before script_counter would reliable see the load of kPrefetchScript, were
+  // it to happen.
+  RequestCounter sentinel_counter;
+  CountRequestFor(kPrefetchScript2, &sentinel_counter);
+  PrerenderTestURL(
+      "/client-redirect/?" +
+          net::EscapeQueryParamValue(MakeAbsolute(kPrefetchPage), false),
+      FINAL_STATUS_APP_TERMINATING, 1);
+  ui_test_utils::NavigateToURL(
+      current_browser(), src_server()->GetURL(MakeAbsolute(kPrefetchPage2)));
+  sentinel_counter.WaitForCount(1);
+  script_counter.WaitForCount(0);
+}
+
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, PrefetchHttps) {
+  UseHttpsSrcServer();
+  RequestCounter main_counter;
+  CountRequestFor(kPrefetchPage, &main_counter);
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  PrerenderTestURL(kPrefetchPage, FINAL_STATUS_APP_TERMINATING, 1);
+  main_counter.WaitForCount(1);
+  script_counter.WaitForCount(1);
+}
+
+// Check that if an SSL error happens we don't fetch.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, SSLError) {
+  // We only send the loaded page, not the loader, through SSL.
+  net::EmbeddedTestServer https_server(net::EmbeddedTestServer::TYPE_HTTPS);
+  https_server.SetSSLConfig(net::EmbeddedTestServer::CERT_MISMATCHED_NAME);
+  https_server.ServeFilesFromSourceDirectory("chrome/test/data");
+  ASSERT_TRUE(https_server.Start());
+  std::unique_ptr<TestPrerender> prerender =
+      PrerenderTestURL(https_server.GetURL(MakeAbsolute(kPrefetchPage)),
+                       FINAL_STATUS_SSL_ERROR, 0);
+  DestructionWaiter waiter(prerender->contents(), FINAL_STATUS_SSL_ERROR);
+  EXPECT_TRUE(waiter.WaitForDestroy());
+}
+
+// We should not have a problem if a subresource fails SSL.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, SSLSubresourceError) {
+  // First confirm that the image loads as expected.
+
+  // Note that we start a separate HTTPS server for the subresource;
+  // src_server() is non-HTTPS.
+  net::EmbeddedTestServer https_server(net::EmbeddedTestServer::TYPE_HTTPS);
+  https_server.SetSSLConfig(net::EmbeddedTestServer::CERT_MISMATCHED_NAME);
+  https_server.ServeFilesFromSourceDirectory("chrome/test/data");
+  ASSERT_TRUE(https_server.Start());
+  GURL https_url = https_server.GetURL("/prerender/image.jpeg");
+  base::StringPairs replacement_text;
+  replacement_text.push_back(
+      std::make_pair("REPLACE_WITH_IMAGE_URL", https_url.spec()));
+  std::string main_page_path;
+  net::test_server::GetFilePathWithReplacements(
+      kPrefetchImagePage, replacement_text, &main_page_path);
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+
+  std::unique_ptr<TestPrerender> prerender =
+      PrerenderTestURL(main_page_path, FINAL_STATUS_APP_TERMINATING, 1);
+  // Check that the presumed failure of the image load didn't affect the script
+  // fetch. This assumes waiting for the script load is enough to see any error
+  // from the image load.
+  script_counter.WaitForCount(1);
+}
+
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, Loop) {
+  RequestCounter script_counter;
+  CountRequestFor(kPrefetchScript, &script_counter);
+  RequestCounter main_counter;
+  CountRequestFor(kPrefetchLoopPage, &main_counter);
+
+  std::unique_ptr<TestPrerender> test_prerender =
+      PrerenderTestURL(kPrefetchLoopPage, FINAL_STATUS_APP_TERMINATING, 1);
+  main_counter.WaitForCount(1);
+  script_counter.WaitForCount(1);
+}
+
+#if defined(ENABLE_TASK_MANAGER)
+
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest,
+                       OpenTaskManagerBeforePrefetch) {
+  const base::string16 any_prerender = MatchTaskManagerPrerender("*");
+  const base::string16 any_tab = MatchTaskManagerTab("*");
+  const base::string16 original = MatchTaskManagerTab("Prefetch Loader");
+  // Presumably we don't see the title in the task manager as the page has not
+  // been fully parsed.
+  const base::string16 prerender =
+      MatchTaskManagerPrerender("*prefetch_page.html*");
+
+  // Show the task manager. This populates the model.
+  chrome::OpenTaskManager(current_browser());
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, any_tab));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(0, any_prerender));
+
+  // Prerender a page in addition to the original tab.
+  PrerenderTestURL(kPrefetchPage, FINAL_STATUS_APP_TERMINATING, 1);
+
+  // A TaskManager entry should appear like "Prerender: Prerender Page"
+  // alongside the original tab entry. There should be just these two entries.
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, prerender));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, original));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, any_prerender));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, any_tab));
+}
+
+#endif  // defined(ENABLE_TASK_MANAGER)
+
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, RendererCrash) {
+  std::unique_ptr<TestPrerender> prerender =
+      PrerenderTestURL(kPrefetchPage, FINAL_STATUS_RENDERER_CRASHED, 1);
+  prerender->contents()->prerender_contents()->GetController().LoadURL(
+      GURL(content::kChromeUICrashURL), content::Referrer(),
+      ui::PAGE_TRANSITION_TYPED, std::string());
+  prerender->WaitForStop();
+}
+
+// For the next two tests, there is nothing for the prefetch scanner to do. But
+// we make sure we behave as expect.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, Png) {
+  RequestCounter counter;
+  CountRequestFor(kPrefetchPng, &counter);
+  PrerenderTestURL(kPrefetchPng, FINAL_STATUS_APP_TERMINATING, 1);
+  counter.WaitForCount(1);
+}
+
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, Jpeg) {
+  RequestCounter counter;
+  CountRequestFor(kPrefetchJpeg, &counter);
+  PrerenderTestURL(kPrefetchJpeg, FINAL_STATUS_APP_TERMINATING, 1);
+  counter.WaitForCount(1);
+}
+
+// We should not prefetch from malware sites.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest,
+                       PrerenderSafeBrowsingTopLevel) {
+  GURL url = src_server()->GetURL(MakeAbsolute(kPrefetchPage));
+  GetFakeSafeBrowsingDatabaseManager()->SetThreatTypeForUrl(
+      url, safe_browsing::SB_THREAT_TYPE_URL_MALWARE);
+  // Prefetch resource are blocked, but the prerender is not killed in any
+  // special way.
+  // TODO(mattcary): do we care about detecting if the main resource is fetched
+  // and preload scanning has started?
+  std::unique_ptr<TestPrerender> prerender =
+      PrerenderTestURL(kPrefetchPage, FINAL_STATUS_APP_TERMINATING, 0);
+}
+
+}  // namespace prerender